Finding Relatives in a Database

1. A method for determining a relative relationship of people who share a common ancestor within a threshold number of generations, comprising: obtaining recombinable deoxyribonucleic acid (DNA) sequence information of a first user and recombinable sequence DNA information of a second user; wherein the recombinable DNA sequence information of the first user and the recombinable DNA sequence information of the second user are stored in a database comprising recombinable DNA sequence information of a plurality of users; determining, using one or more computer processors, based at least in part on a comparison of the recombinable DNA sequence information of the first user and the recombinable DNA sequence information of the second user, a predicted degree of relative relationship that corresponds to a number of generations within which the first user and the second user share a common ancestor; and notifying at least the first user about the relative relationship with the second user.

2. The method of claim 1 , wherein the threshold number of generations is preconfigured; and determining the predicted degree of relationship includes determining whether the number of generations within which the first user and the second user share a common ancestor at least meets the threshold number of generations.

3. The method of claim 1 , wherein the recombinable DNA sequence information includes autosomal DNA sequence information.

4. The method of claim 1 , wherein the recombinable DNA sequence information includes X chromosome DNA sequence information.

5. The method of claim 1 , wherein the predicted degree of relative relationship indicates that the first user and the second user share a common ancestor at least three generations out or beyond.

6. The method of claim 1 , further comprising sending, via a user interface, an invitation to connect from said at least one user to the other user.

7. The method of claim 1 , wherein: determining the predicted degree of relationship between the first user and the second user includes identifying one or more Inheritance By Descent (IBD) regions in which a portion of recombinable DNA sequence of the first user and a portion of recombinable DNA sequence of the second user arose from same DNA sequence of an ancestor; the predicted degree of relationship depends at least in part on an amount of DNA sequence information of the IBD regions; the amount of DNA sequence information of the IBD regions includes a sum of the lengths of IBD regions, percentage of DNA shared in the IBD regions, or both; and a greater amount of DNA sequence information of the IBD regions indicates a closer predicted degree of relationship.

8. The method of claim 1 , wherein determining a predicted degree of relationship between the first user and the second user includes using a distribution pattern that indicates a distribution of amounts of DNA shared by individuals and corresponding relative relationships to determine the predicted relative relationship or a range of relative relationships.

9. The method of claim 8 , wherein the distribution pattern is an initial distribution pattern, and the initial distribution pattern is adjusted based on a population group to which at least one of the users belongs, and the population group is associated with a corresponding distribution pattern that is different from the initial distribution pattern.

10. The method of claim 1 , wherein the DNA sequence information includes single-nucleotide polymorphism (SNP) information.

11. The method of claim 10 , wherein the SNP information includes unphased genotype information.

12. The method of claim 7 , wherein identifying one or more IBD regions includes: identifying consecutive opposite-homozygous calls in a SNP sequence of the first user and in a SNP sequence of the second user, wherein the first user and the second user have opposite-homozygous calls at a given SNP location where the first user and the second user do not share an allele; determining, based at least in part on a distance between the consecutive opposite-homozygous calls, whether a region between the opposite-homozygous calls is an IBD region.

13. The method of claim 12 , wherein the distance is a genetic distance.

14. The method of claim 10 , wherein the SNP sequence information includes phased genotype information.

15. The method of claim 14 , further comprising: storing a first plurality of SNP sequence words that corresponds to SNP sequence information of the first user in one or more hash tables, wherein a SNP sequence word includes encoded SNP sequence information stored in an array; and wherein the comparison of the recombinable DNA sequence information of the first user and the recombinable DNA sequence information of the second user includes determining whether one or more consecutive SNP sequence words in a second plurality of SNP sequence words of the second user matches one or more consecutive SNP sequence words stored in said one or more hash tables.

16. The method of claim 1 , wherein the DNA sequence information comprises genotype information, and the method further comprises correcting genotyping error in the DNA sequence information.

17. The method of claim 1 , wherein the relative relationship is one of a range of possible relative relationships between the first user and the second user, and wherein notifying includes sending an indication of the range of possible relative relationships between the first user and the second user.

18. The method of claim 1 , wherein notifying includes sending, via a network, an indication of a predicted relationship.

19. The method of claim 2 , wherein the threshold number of generations corresponds to is a minimum predicted degree of relationship.

20. The method of claim 1 , further comprising providing the second user with an option to be contacted by potential relatives, and wherein notifying is performed only if the second user has agreed to be contacted by potential relatives.

21. The method of claim 1 , wherein: the first user has a known characteristic; and the method further comprises inferring that the second user has the same characteristic given that the first user and the second user are related and the known characteristic is likely shared by people who are related.

22. The method of claim 7 , wherein: the first user has a known characteristic that is a genotype or a phenotype associated with one or more genes in the one or more IBD regions; and the method further comprises inferring that the second user has the same characteristic given that the first user and the second user share said one or more IBD regions.

23. The method of claim 22 , wherein the characteristic is an inherited disease.

24. The method of claim 1 , further comprising determining a relative relationship of a third user with respect to the first user, a relative relationship of the third user with respect to the second user, or both; inferring or refining a relative relationship between the first user and the second user given the relative relationship information of a third user with respect to the first user, the relative relationship of the third user with respect to the second user, or both, and given the predicted degree of relative relationship between the first user and the second user.

25. The method of claim 1 , further comprising: determining a relative relationship of a third user with respect to the second user; inferring an additional relative relationship or refining an existing predicted relative relationship between the first user and the third user, given the predicted degree of relative relationship between the first user and the second user, and given the relative relationship of the third user with respect to the second user.

26. A system for determining a relative relationship of people who share a common ancestor within a threshold number of generations, comprising: one or more processors configured to: receive recombinable deoxyribonucleic acid (DNA) information of a first user and recombinable DNA sequence information of a second user; wherein the recombinable DNA sequence information of the first user and the recombinable DNA sequence information of the second user are stored in a database comprising recombinable DNA sequence information of a plurality of users; determine, based at least in part on a comparison of the recombinable DNA sequence information of the first user and the recombinable DNA sequence information of the second user, a predicted degree of relationship that corresponds to a number of generations within which the first user and the second user share a common ancestor; and notify at least the first user about a relative relationship with the second user; and a memory coupled to at least some of the one or more processors, configured to provide the processors with instructions.

27. A computer program product for determining a relative relationship of people who share a common ancestor within a threshold number of generations, the computer program product being embodied in a tangible computer readable storage medium and comprising computer instructions for: receiving recombinable deoxyribonucleic acid (DNA) sequence information of a first user and recombinable DNA sequence information of a second user; wherein the recombinable DNA sequence information of the first user and the recombinable DNA sequence information of the second user are stored in a database comprising recombinable DNA sequence information of a plurality of users; determining, based at least in part on a comparison of the recombinable DNA sequence information of the first user and the recombinable DNA sequence information of the second user, a predicted degree of relationship that corresponds to a number of generations within which the first user and the second user share a common ancestor; and notifying at least the first user about a relative relationship with the second user.

28. The system of claim 26 , wherein the recombinable DNA sequence information includes autosomal DNA sequence information.

29. The system of claim 26 , wherein the recombinable DNA sequence information includes X chromosome DNA sequence information.

30. The system of claim 26 , wherein the one or more processors are further configured to send an invitation to connect from said at least one user to the other user.

31. The system of claim 26 , wherein to determine the predicted degree of relationship between the first user and the second user includes to identify one or more Inheritance By Descent (IBD) regions in which a portion of recombinable DNA sequence of the first user and a portion of recombinable DNA sequence of the second user arose from same DNA sequence of an ancestor; the predicted degree of relationship depends at least in part on an amount of DNA sequence information of the IBD regions; the amount of DNA sequence information of the IBD regions includes a sum of the lengths of IBD regions, percentage of DNA shared in the IBD regions, or both; and a greater amount of DNA sequence information of the IBD regions indicates a closer predicted degree of relationship.

32. The system of claim 26 , wherein the relative relationship is one of a range of possible relative relationships between the first user and the second user, and wherein to notify includes to send an indication of the range of possible relative relationships between the first user and the second user.

33. The system of claim 26 , wherein the one or more processors are further configured to provide the second user with an option to be contacted by potential relatives, and wherein notifying is performed only if the second user has agreed to be contacted by potential relatives.

34. The computer program product of claim 27 , wherein the recombinable DNA sequence information includes autosomal DNA sequence information.

35. The computer program product of claim 27 , wherein the recombinable DNA sequence information includes X chromosome DNA sequence information.

36. The computer program product of claim 27 , further comprising computer instructions for sending an invitation to connect from said at least one user to the other user.

37. The computer program product of claim 27 , wherein determining the predicted degree of relationship between the first user and the second user includes identifying one or more Inheritance By Descent (IBD) regions in which a portion of recombinable DNA sequence of the first user and a portion of recombinable DNA sequence of the second user arose from same DNA sequence of an ancestor; the predicted degree of relationship depends at least in part on an amount of DNA sequence information of the IBD regions; the amount of DNA sequence information of the IBD regions includes a sum of the lengths of IBD regions, percentage of DNA shared in the IBD regions, or both; and a greater amount of DNA sequence information of the IBD regions indicates a closer predicted degree of relationship.

38. The computer program product of claim 27 , wherein the relative relationship is one of a range of possible relative relationships between the first user and the second user, and wherein notifying includes sending an indication of the range of possible relative relationships between the first user and the second user.

39. The computer program product of claim 27 , further comprising computer instructions for providing the second user with an option to be contacted by potential relatives, and wherein notifying is performed only if the second user has agreed to be contacted by potential relatives.